Weeds that grow in, e.g., the spaces between fields readily serve as nests for pests, and therefore operations for cutting these weeds must often be performed, particularly during the period in which the weeds are growing. This operation involves heavy labor, and therefore a variety of work machines have been proposed and put into use. Bush cutters are work machines that are small-sized and readily used, and are therefore widely employed. Typical bush cutters have a rotating shaft passing through a pipe-shaped operating rod and use a motor provided to the rearward end of the operating rod to cause the rotating shaft to rotate, whereby a cutting blade provided to the forward end of the operating rod is made to rotate. The operator suspends the bush cutter from one shoulder so that the operating rod extends diagonally forwards along the hips (the lateral part) of the body, grips the operating handle provided to the middle of the operating rod, and sweeps the operating rod up, down, left, and right, whereby the cutting blade cuts the weeds.
In order to lighten the burden on the operator and increase the efficiency of the operation, the cutting blade is preferably oriented in front of the body so that left and right sweeping motions of the body are limited to the extent possible, and leaning movements are eliminated during the bush-cutting operation. However, the operating rod interferes with the body of the operator in most bush cutters. Brush cutters in which the operating rod does not interfere with the body of the operator are accordingly well-known, as disclosed in Japanese Utility Model Application Post0-Exam Publication No. 30-11418 (JP-U 30-11418 B), Japanese Patent Application Laid-Open Publication No. 2002-354921 (JP 2002-354921 A), and Japanese Patent Application Laid-Open Publication No. 2002-354922 (JP 2002-354922 A).
The bush cutter disclosed in JP-U 30-11418 B is a detached model in which the engine for rotating the cutting blade is detached. The engine is borne on the back of the operator, and the operator cuts rice plants, wheat, and the like while grasping the rearward end of the operating rod in front of the body, extending the operating rod forward, and sliding the forward-end portion of the operating rod on the ground. The bush cutter disclosed in JP-U 30-11418 B is thus not a model in which the operator performs operations while the operating rod is suspended from the shoulder. In other words, the bush cutter of JP-U 30-11418 B is used by sliding the forward-end portion of the operating rod along the ground and is therefore not appropriate for bush-cutting operations in sloping or uneven locations.
The bush cutters disclosed in JP 2002-354921 A and JP 2002-354922 A are models in which the operator performs operations while the operating rod is suspended from the shoulder. The operating rod is a folding type composed of a forward-half part to which the cutting blade and a cutting-drive motor are provided, and a rearward-half part to which a motor battery is provided. The forward end of the rearward-half part can be tilted laterally relative to the rearward end of the forward-half part that has the operating handle. The operator grasps the operating handle in front of the body and extends the forward-end part forward, whereby the cutting blade can be oriented in front of the body. However, the rearward-half part interferes with the body in this position, and the rearward-half part is therefore tilted laterally in the non-interfering range.
However, the heavy battery of the aforedescribed bush cutter is offset to the left or right relative to the forward-half part. The center of gravity of the bush cutter is therefore offset to the left or right relative to the width-wise center of the body of the operator, and therefore the lateral weight balance of the bush cutter relative to the body is inadequate. Further improvements are therefore possible in order to lighten the burden on the operator and increase the efficiency of the operation.